This invention relates to a connection module and a connector. In particular, the invention relates to a connector and to a connection module for use in connecting instrumentation equipment to a fluid container such as a process line or pressure vessel.
Within the instrumentation industry, it is necessary to take fluid from a fluid container such as a process pipeline or pressure vessel, so as to take measurements of quantities such as pressure, temperature, flow and fluid level measurements.
The instruments which are used to take such measurements are typically connected to a fluid container by a system of pipes, manifolds and valves. The connection system can include one or more tapping connections for tapping the fluid container.
The instruments which are used to take such measurements require maintenance, such as calibration. In order to carry this out it is necessary to modify the flow of the fluid between the fluid container and the instrument.
This flow modification is currently carried out by a number of methods all of which in some way require systems which are attached to the main process apparatus by means of threaded, flanged or welded connections. Traditionally the fluid passes through an isolation valve before being passed through tubing, pipe work or flanges to other valves commonly held within a manifold block. This manifold block may either be attached directly to the instrument or attached via a further system of tubing or pipe work. Known arrangements are complicated and require a large amount of time and effort to install and remove. This makes maintenance of instruments costly, since to remove and then reattach an instrument to a fluid container can actually take longer than the calibration process itself.
A number of other problems are associated with the traditional installation methods.
For example, traditional connection systems are bulky. These systems require a lot of space and are weighty. Indeed, such systems require additional support due to their weight.
Manifold systems traditionally have small orifice sizes typically less than 6 mm—this can cause a number of system problems such as becoming clogged by solid particles within a system.
The phenomena known as gauge line error (GLE) is known in the industry as a potential source of error. This is caused by a combination of the distance between the main process fluid and the instrument, the reduced bore sizes and the level of turbulence caused by the shear quantity of connections between the individual elements of the system. Turbulence associated with GLE can inhibit accurate measurement by an instrument connected to a fluid container. Reducing the path length for fluid flow between a fluid container and a instrument can reduce turbulence and therefore GLE. Known systems struggle to provide a short path length. Longer path lengths also make leaks more probable and more difficult to find.
Due to the distance between the fluid container and the instrument, and the need to keep an adequate level of viscosity within the fluid, it is sometimes necessary to heat the system including all manifolds and tubing or piping. This process can include a number of costly methods including cladding, electrical heating systems or steam-heated systems. These systems result in additional weight, space requirements and additional control systems resulting in higher costs.
An example of a fluid container is a pipeline. FIG. 1 shows an example of a pipeline 2, which includes an orifice plate assembly 10. The orifice plate assembly 10 includes two flanges 4 forming a flanged connection. The orifice plate assembly 10 also includes a plate 6 held between the two flanges 4. The plate includes an aperture which is smaller than an inner diameter of the pipeline 2, and is thus designed to reduce the flow of the fluid passing through the pipeline 2.
In such an arrangement, fluid can be passed to an instrument via tapping points. In the example shown in FIG. 1, suitable tapping points are indicated by the arrows 8. These tapping points 8 are located one on either side of the plate.
Pipelines of this kind are relatively crude in construction and thus tapping connection ports provided at the tapping points 8, although conforming with relevant international standards, can be misaligned with respect to one another. This misalignment can be present in all six degrees of freedom (three translational and three rotational directions). Thus, one of the tapping connectors may be misaligned with respect to another tapping connector in any of the x, y or z directions indicated in FIG. 1. The tapping connectors may also be misaligned in the sense that they are skewed (angled). Accordingly, one of the tapping connectors may be misaligned with respect to another tapping connector in any of the rotational directions (θx, θy, θy) indicated in FIG. 1.
This misalignment has previously been addressed in traditional connection systems by simply adding additional bends to the tubing or pipe work to account for the misalignment.
Traditional connection systems include separate components that are typically obtained from different suppliers. The different components can perform different functions. For example, a connection component can connect directly to a fluid container. A manifold component including valves and so forth can be provided intermediate a connection component and an instrument component. The instrument component can provide a connection to a variety of instrument types, or can itself include an instrument.
The components of such a system need to be inter-connectable. For example, a manifold block may either be attached directly to an instrument or attached via a further system of tubing or pipe work to a fluid container. The connections must ensure leak free service. The connections must also be capable of accepting additional loads subjected by means of external forces. The joint should also be non-permanent to allow for maintenance.
Traditional connections between the various components of an instrumentation system employ threaded connections or flange arrangements.
Threaded connections suffer from problems with orientation. Also, users in the offshore industries have a tendency to doubt threaded connections due to issues of crevice corrosion and other ‘hidden’ issues. Moreover, threaded connections are normally limited to small sizes up to around 50 mm (2″) in diameter.
Flanged connections entail large space requirements and are weighty. Systems which use flanged connections require additional support due to their weight.
All of the problems indicated above are exacerbated by the large number of connections which may be required and the high operating pressures of many pipelines and pressure vessels. In an installation (for example a refinery) which employs many fluid containers (pressure vessels, pipelines etc.), a large number of connections may be needed to attach various instruments for monitoring quantities such as pressure and fluid flow. As indicated above, known connection arrangements are cumbersome and require a large amount of time and effort for connecting and disconnecting instruments, for example to carry out maintenance. Where many instruments and connections are provided, connection and disconnection times are an important consideration.